HELP!!! Does anyone know anything about significant figures? It’s in chemistry…I’m really having a hard time…please help :eek:

Sig figs…

Any 0 after the last digit (.60 or 100) doesn’t count as a sig fig.

The exception to that is if there is a decimal point after the last 0 (100.), this will make the numbers count as sig figs.

Any 0 in between digits (.06) counts as a sig fig.

All numbers count as sig figs otherwise (125 or 12.56)

When adding numbers with dif numbers of sig figs (10.2 + 11) you always go down to the least number of sig figs (= 21).

That’s a few of the rules. The others should be in your book or your notes. What’s your problem with sig figs?

Originally posted by Sinistral

When adding numbers with dif numbers of sig figs (10.2 + 11) you always go down to the least number of sig figs (= 21).

Actually, when adding or subtracting, you take the answer, and round it off to the number used in the addition/subtraction with the least amount of <b>decimals</b>, i.e. 311 + 0.6 = 312, 130000 + 8559.66 = 140000

When multiplying you go round the answer to the least amount of <b>significant digits</b> of numbers used in the multiplication/division

i.e. 10000 x 3.642624873 = 40000

my bad

thanks for the info…

Also, you do count trailing zeros if they are after the decimal place. For example, .60 is significant to the hundredths place and has two significant figures. This is not standard form. In standard form, it would be 6.0 * 10^-1. In standard form, all zeros are significant since they are always after the decimal (a non-zero number in the ones place, followed by numbers after the decimal place, and the 10 raised to a power).

In non-standard form, if you have a number like 100 significant to the tens place, you would put a line over the last significant zero. in standard form, it would be written 1.0 * 10^2.